The table plan, auction catalogue, and briefing notes for the event were leaked to the BIJ. Although expensive fundraising dinners are nothing new, this one raises eyebrows because of the sheer wealth gathered around Cameron's table: His supporters at the dinner were worth a combined £11 billion ($18.8 billion), according to the BIJ. They later donated £5 million to the Conservative Party, the Mail says.

The dinner — held at the former fishmarket at Old Billingsgate — was also a complete secret. One attendee was given these instructions to keep his mouth shut: "You are absolutely forbidden from reporting any details of this event using any kind of social media. Sorry to be a bore but it is imperative no member of our team lets the side down," the organizer wrote.

Vasily Shestakov, Putin's judo partner, who is also member of the Russian parliament.

Three other wealthy Russian businessmen and one former financier who was exiled from the country.

Paul Staines, the writer who runs the Guido Fawkes political blog.

London Mayor Boris Johnson and two other members of the Bullingdon Club, the exclusive Oxford University society to which Cameron and Johnson belonged — which Cameron has tried to distance himself from.